textproduct: Quad Cities

KEY MESSAGES

- Heat and humidity returns this weekend and into early next week. Heat indices around or exceeding 100 degrees are becoming increasingly likely (40-70%) Sunday and Monday, and an Extreme Heat Watch has been issued for those days.

- Thunderstorms are possible (30-50% chance) Sunday evening into Monday and may be strong to severe. The SPC has issued a Marginal-to-Slight Risk (Level 1 to 2 out of 5) for severe weather with damaging winds being the primary hazard.

SHORT TERM /THROUGH SATURDAY NIGHT/

Issued at 246 PM CDT Fri Jul 24 2026

Enjoy the last day of mild July conditions as the high pressure over our area drifts eastward and southwesterly flow sets in this weekend. Temperatures this afternoon in the mid-to-upper 70s will only fall into the low-to-mid-60s tonight as a stratocumulus deck supported by low-level WAA and a weak shortwave trough moves into the CWA. Heading into Saturday, morning cloud cover should slow diurnal warming, but highs are still expected in the mid-to-upper 80s. Dew points will slowly rise throughout the day though into the low-to-mid-70s. The additional moisture is expected to put a floor on diurnal cooling Saturday night despite the clearing skies as lows only drop into the upper 60s to low 70s, setting up the potential for dangerous heat heading into Sunday and Monday.

LONG TERM /SUNDAY THROUGH THURSDAY/

Issued at 246 PM CDT Fri Jul 24 2026

Sunday...The warming trend continues into Sunday as the upper- level ridge over the Southern Rockies sits in place. A ridge- riding trough is forecasted to dive into south-central Canada, deepening a low pressure system and forcing a cold front down into the Northern Plains. Southwesterly flow and low-level WAA intensify, allowing highs to soar into the low-to-mid-90s with heat indices potentially (40-70% chance) exceeding 100 degrees. An Extreme Heat Watch has been issued for all of eastern Iowa, west-central Illinois, and northwest Missouri for this heat threat. By Sunday night, the cold front could reach northwestern Iowa as our cloud cover and PoPs increase overnight. There is some ensemble signal of a MCS development across northern Iowa that could move southeastward into our CWA, but uncertainty remains high with PoPs only sitting at 30-50% north of Interstate 80. Despite this, SPC did issue a Slight Risk (Level 2 out of 5) for the Highway 20 corridor and a Marginal Risk (Level 1 out of 5) for the rest of the CWA for the potential (5-15% chance) for damaging winds with any thunderstorm complex that develops. The additional cloud cover should limit lows to the mid-to-upper 70s, and once again, setting up the potential for dangerous heat Monday ahead of the cold front.

Monday...The shortwave trough continues to dive southeastward into the Great Lakes region as the cold front inches towards our CWA by Monday afternoon. Dry air advection in the mid levels behind Sunday night's convection is forecasted to suppress PoPs (10-20% coverage) along the actual surface front. With such warm overnight lows, highs should easily reach the low-to- mid-90s again (70-100% chance), especially in southeast Iowa, west-central Illinois, and northwest Missouri. Convergence along the cold front could support moisture pooling with dew points reaching the upper 70s ahead of the boundary. This will lead to localized maxima in heat indices throughout Monday afternoon with areas along and southwest of a line between the Quad Cities and Waterloo possibly seeing heat indices exceeding 105 degrees (30-50% chance) and is why the Extreme Heat Watch extends through Monday evening as well. As the cold front clears the area Monday night, northwesterly flow is expected to advect in slightly cooler, drier air as dew points drop back into the upper 60s and lower 70s.

Tuesday-Thursday...As another high pressure moves in and sits over Iowa, conditions are likely (50-80%) to be quiet Tuesday into Wednesday with mostly clear skies, highs in the upper 80s to low 90s, and lows in the mid-60s to low 70s. Current LREF guidance has the ridge over the Southern Rockies retrograding slowly to the west throughout the middle of next week. This opens the door for another shortwave to slide southeastward into the Upper Mississippi River Valley on Thursday and introduces PoPs (10-20% coverage) back into the forecast.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 132 PM CDT Fri Jul 24 2026

VFR conditions are expected over the next 6 hours as a FEW to SCT diurnal cumulus deck affects CID, DBQ, and MLI and a BKN mid-level cloud deck sits over BRL. A stratocumulus deck is forecasted to move in from the west overnight and lower throughout the night with MVFR conditions likely (60-80%) and periods of IFR ceilings closer to sunrise (30-60% chance) which prompted TEMPOs being included. In the lowest cloud decks, there is the possibility (30-40% chance) of visibility less than 5SM, but the low confidence led to its exclusion from this TAF issuance. South-to-southeasterly winds of 5-10 knots are expected to slowly subside overnight and turn variable after midnight.

DVN WATCHES/WARNINGS/ADVISORIES

IA...Extreme Heat Watch from Sunday afternoon through Monday evening for IAZ040>042-051>054-063>068-076>078-087>089- 098-099. IL...Extreme Heat Watch from Sunday afternoon through Monday evening for ILZ009-015>018-024>026-034-035. MO...Extreme Heat Watch from Sunday afternoon through Monday evening for MOZ009-010.